The transfer of 137 Cs, Pu isotopes and 90 Sr to bird, bat and ground-dwelling small mammal species within the Chernobyl exclusion zone

Abstract

Protected species are the focus of many radiological environmental assessments. However, the lack of radioecological data for many protected species presents a significant international challenge. Furthermore, there are legislative restrictions on destructive sampling of protected species to obtain such data. Where data are not available, extrapolations are often made from 'similar' species but there has been little attempt to validate this approach. In this paper we present what, to our knowledge, is the first study purposefully designed to test the hypothesis that radioecological data for unprotected species can be used to estimate conservative radioecolgical parameters for protected species; conservatism being necessary to ensure that there is no significant impact. The study was conducted in the Chernobyl Exclusion Zone. Consequently, we are able to present data for Pu isotopes in terrestrial wildlife. There has been limited research on Pu transfer to terrestrial wildlife which contrasts with the need to assess radiation exposure of wildlife to Pu isotopes around many nuclear facilities internationally. Our results provide overall support for the hypothesis that data for unprotected species can be used to adequately assess the impacts for ionising radiation on protected species. This is demonstrated for a range of mammalian and avian species. However, we identify one case, the shrew, for which data from other ground-dwelling small mammals would not lead to an appropriately conservative assessment of radiation impact. This indicates the need to further test our hypothesis across a range of species and ecosystems, and/or ensure adequate conservatism within assessments. The data presented are of value to those trying to more accurately estimate the radiation dose to wildlife in the Chernobyl Exclusion Zone, helping to reduce the considerable uncertainty in studies reporting dose-effect relationships for wildlife. A video abstract for this paper is available from: http://bit.ly/1JesKPc.

Impacts of radiation exposure on the bacterial and fungal microbiome of small mammals in the Chernobyl Exclusion Zone

“…Animals were live-monitored to determine whole-body radionuclide activity concentrations and hence enable estimation of internal dose. While there is a potential for some external contamination (of skin and fur) to influence live-monitoring results, skinned carcasses and whole animal live-monitoring data from some of our previous small mammal studies in the CEZ (Beresford et al, 2008(Beresford et al, , 2016 demonstrate that surface contamination makes a negligible contribution to the whole-body activity concentration measurements obtained via live monitoring. Consequently, this is not a significant source of uncertainty for the present study.…”

Modelling the effects of ionising radiation on a vole population from the Chernobyl Red forest in an ecological context

“…This approximation is valid because 40 K, 60 Co, 134 Cs, 154 Eu, 238,239,240 Pu and 241 Am concentrations in soil were lower by 2-3 orders of magnitude than 90 Sr and 137 Cs (Gaschak et al, 2011). The bioavailability of actinides to small mammals is low (Beresford et al, 2016) and, at present, 90 Sr and 137 Cs are the main contributors to the total dose rate experienced by small mammals in the Red Forest (Beresford et al, 2019).…”

Radiation databases and archives – examples and comparisons

“…This organization is an important funder of universities and other institutions engaged in research in environmental science. For example, both the dataset from research on vertebrates from the Chernobyl exclusion zone (Gaschak et al 2018) and information about research projects that utilized the data (STAR database 2013; Barnett 2009 et al;Beresford et al 2011;Beresford et al 2008;Beresford et al 2016) are available via NERC through Open Government License. The data is accessible through the STORE database as well.…”